Given the resonant scattering nature of the Ly\(\alpha \)  line, the emergent
profile is modified and suppressed by many physical effects, e.g. H i content, gas geometry and kinematics, and the dust content and
distribution. For instance, in an optically-thick static medium Ly\(\alpha \)  escapes through successive resonance scattering leading to a
double-humped profile, with the position of the peaks determined by
column density, temperature, and kinematics of the medium
[1]}, [2]}. In
addition, scattering through an inflowing (outflowing) medium leads to
an overall blueshift (redshift) of the Ly\(\alpha \)  profile with enhanced blue
(red) peak and suppressed red (blue) peak
[3]}. In a pure static medium, the
expected velocity offset of the Ly\(\alpha \)  emission is \(\sim \)  344 km s\(^{-1}\)  if
we assume H i gas temperatures of \(10^4\)  K [2]}. For a column density of
\(10^{21}~\rm cm^{-2}\) , consistent with this DLA, a velocity of
\(\approx 300~\rm km~s^{-1}\)  is expected, in line with our observations
(\(\approx 281\)  km s\(^{-1}\)  with respect to the systemic redshift derived
from metal absorption lines).
